Electric incandescent lamp filament support



Jan. 24, 1967 z. DESHAW 3,300,675

ELECTRIC INCANDESCENT LAMP FILAMENT SUPPORT Filed April 5, 1964 FIG. 7.

United States Patent M 3,300,675 ELECTRIC INCANDESCENT LAMP FILAMENTSUPPORT Zoltan Deshaw, 18 St. James Mansions, London, England Filed Apr.3, 1964, Ser. No. 357,211 2 Claims. (Cl. 313-274) This invention relatesto electric incandescent filament lamps of strip form.

In referring to strip-form lamps I mean lamps of generally tubular form,along the length-wise direction of which the filament extends. Suchlamps include strip lamps with contacts at opposed ends of the tube, andso called tubular and other lamps having the contacts at one end, thefilament in this case extending from one electrode, along the tube inone direction and then back again to the other electrodes.

Hitherto the ends of the filament in line filament tubular lamps havebeen connected to conductive wires which are attached to the end of afilament supporting spine, e.g., a glass rod, and provide endpole-pieces onto which the electrodes projecting from the electrodemounts at the opposed ends of the lamp tube are connected. Inmanufacture the end pole-pieces are connected to the spine, the filamentis connected in place between the pole-pieces, and the electrodes on thetwo electrode mounts are then connected to the pole-pieces prior toinsertion of the assembly into the tubular lamp envelope, sealing of theelectrode mounts to the tube, exhausting of the lamp and fitting of thelamp caps.

An object of this invention is to simplify the manufacture.

Another object of the invention is a strip-form electric incandescentfilament lamp in which the line filament is connected directly to theelectrodes.

A further object of the invention is a strip form electric incandescentfilament lamp in which a supporting spine for the line filament isdirectly supported by the lamp electrodes.

These and other objects of the invention will be apparent from thefollowing description of particular embodiments thereof which are shownby way of example in FIGURES 2 and 3 of the accompanying drawings, whichfigures show one end portion of a double-ended tubular lamp and one endportion of a single-ended tubular lamp respectively. FIGURE 1 of thedrawings shows one end portion of a double-ended tubular lampconstructed in the manner usual before the present invention.

In the known double-ended filament lamp (FIGURE 1) the line filament 1is connected at its ends to wire pole-pieces 2 attached to the ends of aglass rod 3 constituting a filament-supporting spine. Only one endportion of the lamp is shown: the other end is identical. For attachingthe pole-pieces 2 to the rod 3, an end portion of each pole-piece isformed into a coil 2a and the wire convolutions are caused elasticallyto grip the rod 3. Between its ends, the filament 1 is supported by therod 3 through the agency of filament support wires 4 which at one endare anchored in the rod 3 and at the other end are pigtailed about thefilament. The inner end of each electrode 5 is bent over and this bentend of the electrode is engaged around the pole-piece 2 at thecorresponding end of the filament.

In the lamp illustrated by FIGURE 2 the use of separate pole-piecesbetween the electrodes and filament is dispensed with. The portion ofeach electrode 5 projecting inwardly from the electrode mount is formed,short of 3,300,675 Patented Jan. 24, 1967 the electrode end, into a coil5a which is caused to grip the rod 3. The free end portion of theelectrode extends normally to the rod and the corresponding end of thefilament 1 is connected directly to the electrode extremity.

The lamp illustrated in FIGURE 3 is a single-ended tubular lamp with twoelectrodes 5, 6 made from fairly hard nickel wire. One of the lampelectrodes (electrode 5) is formed for supporting one end of the rod 3as in the lamp shown in FIGURE 2, and is directly connected to one endof the lamp filament 1. The second electrode (electrode 6), extendsalong the interior of the rod 3 (which is hollow) from the lamp cap, andbeyond the remote end of the rod the electrode is formed into a loop 6bshaped to nest into the conical end of the lamp envelope. Nearer itsextremity the electrode 6 is formed into a coil 6a which grips thecorresponding end of the rod 3 and the end portion of the electrodesextending from the coil 6a forms a pole-piece to which the correspondingend of the filament 1 is directly connected. The loop 6b which is formedfrom the resilient nickel wire, helps to avoid vibration of the mountedfilament.

As compared with lamps according to FIGURE 1, the mounting of thefilaments illustrated in FIGURES 2 and 3 is much easier and more securesince the jointing of the electrodes to separate pole-pieces as bywelding or hooking, is obviated. Not only is the manufacture simplified,but the electrical connection between electrodes and filament and themechanical support of the electrodesupporting spine member are improved.

It is to be understood that the embodiments hereinbefore described areillustrative only and various alternative constructions are possiblewithin the scope of the invention as defined by the appended claims. Inparticular it is mentioned that the lamp according to FIGURE 3 could bemodified by extending the end of the spine which is remote from the endcap, into contact with the adjacent end portion of the lamp envelope sothat this envelope supports that end of the spine, in which case theelectrode 6 need not be formed for supporting that spine end.

What I claim is:

1. An electric incandescent lamp having a generally tubular envelope, anend cap at one end of said envelope, a filament extending along theinterior of said envelope, an electrically insulating filament supportcomprising a tubular spine, a first electrode extending from said capand into engagement with the nearer end of said spine so as to supportsuch spine away from said envelope while leaving an end portion of suchelectrode projecting from said spine, which end portion is directlyconnected to one end of said filament, and a second electrode extendingfrom said cap, along the interior of said spine, and into contact withthe said envelope and the end of said spine which is remote from saidend cap thereby to support that spine end away from said envelope whileleaving an end portion of said second electrode which projects laterallyfrom said spine and is directly connected to the other end of saidfilament.

2. An electric incandescent lamp having an elongated generally tubularenvelope, an end cap on said envelope, a filament extending along theinterior of said envelope, electrodes each having its outer endconnected to said end cap and its inner end connected directly to thenearer end of said filament, and a longitudinal filament-supportingspine carrying filament-supporting wires which support said filament ata predetermined position between its 3 4 ends, said electrodes beingformed intermediate their ends 2,087,759 7/1937 Gaidies 313204 X intocoils which surround the end portions of the spine 2,424,457 7/1947Haynes et a1 313-288 X and support it in spaced relation to the lampenvelope. 2,425,864 8/ 1947 Cartun 313-285 X References Cited by theExaminer 5 FOREIGN PATENTS 1,061,120 11/1953 France. UNITED STATESPATENTS 1,140,716 5/ 1957 France.

988,416 4/1911 Welsh 313374 1,885,431 11/1932 Grow 313 284 X JOHN W-HUCKERT, Prlmarw Exammer- 1,993,829 3/1935 Chapman 313274 10 A. J.JAMES, Assistant Examiner.

1. AN ELECTRIC INCANDESCENT LAMP HAVING A GENERALLY TUBULAR ENVELOPE, ANEND CAP AT ONE END OF SAID ENVELOPE, A FILAMENT EXTENDING ALONG THEINTERIOR OF SAID ENVELOPE, AN ELECTRICALLY INSULATING FILAMENT SUPPORTCOMPRISING A TUBULAR SPINE, A FIRST ELECTRODE EXTENDING FROM SAID CAPAND INTO ENGAGEMENT WITH THE NEARER END OF SIAD SPINE SO AS TO SUPPORTSUCH SPINE AWAY FROM SAID ENVELOPE WHILE LEAVING AN END PORTION OF SUCHELECTRODE PROJECTING FROM SAID SPINE, WHICH END PORTION IS DIRECTLYCONNECTED TO ONE END OF SAID FILAMENT, AND A SECOND ELECTRODE EXTENDINGFROM SAID CAP, ALONG THE INTERIOR OF SAID SPINE, AND INTO CONTACT WITHTHE SAID ENVELOPE AND THE END OF SAID SPINE WHICH IS REMOTE FROM SAIDEND CAP THEREBY TO SUPPORT THAT SPINE END AWAY FROM SAID ENVELOPE WHILELEAVING AN END PORTION OF SAID SECOND ELECTRODE WHICH PROJECTS LATERALLYFROM SAID SPINE AND IS DIRECTLY CONNECTED TO THE OTHER END OF SAIDFILAMENT.